| From 50f06b3efb638efb0abd95dc62dca05ae67882c2 Mon Sep 17 00:00:00 2001 |
| From: Nick Wellnhofer <wellnhofer@aevum.de> |
| Date: Fri, 7 Aug 2020 21:54:27 +0200 |
| Subject: [PATCH] Fix out-of-bounds read with 'xmllint --htmlout' |
| |
| Make sure that truncated UTF-8 sequences don't cause an out-of-bounds |
| array access. |
| |
| Thanks to @SuhwanSong and the Agency for Defense Development (ADD) for |
| the report. |
| |
| Fixes #178. |
| |
| CVE: CVE-2020-24977 |
| Upstream-Status: Backport [https://gitlab.gnome.org/GNOME/libxml2/-/commit/50f06b3efb638efb0abd95dc62dca05ae67882c2] |
| |
| Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com> |
| --- |
| xmllint.c | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| diff --git a/xmllint.c b/xmllint.c |
| index f6a8e463..c647486f 100644 |
| --- a/xmllint.c |
| +++ b/xmllint.c |
| @@ -528,6 +528,12 @@ static void |
| xmlHTMLEncodeSend(void) { |
| char *result; |
| |
| + /* |
| + * xmlEncodeEntitiesReentrant assumes valid UTF-8, but the buffer might |
| + * end with a truncated UTF-8 sequence. This is a hack to at least avoid |
| + * an out-of-bounds read. |
| + */ |
| + memset(&buffer[sizeof(buffer)-4], 0, 4); |
| result = (char *) xmlEncodeEntitiesReentrant(NULL, BAD_CAST buffer); |
| if (result) { |
| xmlGenericError(xmlGenericErrorContext, "%s", result); |
| -- |
| 2.17.1 |
| |